Diesel fuel



Patented Mar. 3, 1942 DIESEL FUEL Louis A. Clarke, Flshkiil, N. Y., assignor, by mesne assignments, to The Texas-Company, New York, N. Y., a corporation of Delaware No Drawing.

. 9 Claims.

This invention relates to liquid fuels for internal combustion engines and has to do particularly with improvements in fuels for compression ignition engines, such as the Diesel or semi-Diesel.

The compression ignition type of engine requires for desirable operation, fuels which have a short time lag between the entrance of the first portion of the fuel into the cylinder and its subsequent auto-ignition. An object of the present invention is to reduce the time lag by lowering the minimum compression ratio necessary for auto-ignition by providing in the fuel a sufllcient amount of an improved primer or ignition accelerator to accelerate the auto-ignition.

The primers contemplated according to the present invention are the nitro halogen derivatives of normally gaseous hydrocarbons. Alkyl derivatives containing only halogen substituents are substantially ineffective as Diesel fuel primers. The nitro derivatives of normally gaseous hydrocarbons are also relatively poor primers except those containing a higher number of nitro groups, but the latter are either unstable or react with the fuel constituents to produce sludge. It has been found that by substituting both halogen and nitro substituents into the normally gaseous hydrocarbons that very efficient Application October 11, 1938, Serial No. 234,360

primers may be obtained which are stable and produce little sludge in the oil to which they are added.

The nitro halogen derivatives of any of the normally gaseous hydrocarbons, such as methane, ethane, propane and butane may be used. The

methane and ethane derivatives are particularly dinitro methane are described in Bielstein, fourth edition, volume 1, page 76. The preparation of chloro-nitro ethane is described in Bielstein, fourth edition, volume 1,-page 101. The polychloro-dinitro ethanes, such as dichloro-dinltro ethane, may be prepared by chlorination of chlorodinitro ethane, by the procedure similar to that given for the preparation of dichloro-dlnitro methane.

The amount of the. primer used is usually, not over 5%, generally between about 1 to 4%, and preferably about 3 or 4% by weight. The amount,

of course, can be varied and it is intended that sufiicient 'amount be used to lower the minimum compression ratio necessary for auto-ignition to the desired extent. It is also to be understood that mixtures of the various compounds herein disclosed may be used.

The following table shows the results obtained by adding various compounds of the present invention to petroleum hydrocarbon oil of Diesel grade. The hydrocarbon fuel alone had a cetane value of 34 and to this ineaoh case was added 4% by weight of the indicated compound:

Octane Primer used numbers 'Iri-chloro-nitrmmethane 52 Di-chloro di-nitro-methane.-. 59 Di-chloro-tetm nitro-ethane 53 Tetra-chloro-di-nitroethanei 51 the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations shouldbe imposed as are indicated'in the appended claims.

I claim:

1. A liquid fuel for compression ignition engines containing a small quantity of trichloronitro methane.

2. An improved Diesel fuel comprising ,a hydrocarbon fuel oil containing about 1.0% by .weight of chloropicrin.

3. An improved Diesel fuel comprising a hydrocarbon fuel oil containing a minor proportion of chloropicrin, suflicient to decrease the ignition delay period of the fuel, improve its'cold starting ability and decrease its tendency to deposit carbon and carbonaceous material in the motor combustion chamber. 7

4. The method of accelerating the ignition of Diesel cycle internal combustion engines which comprises admixing with the fuel, prior to ignition, a minor proportion of chloropicrin.

5. The method of accelerating the ignition of a Diesel cycle internal combustion engine which comprises introducing chloropicrin to the combustion chamber ofthe engine, simultaneously I Diesel fuel.

6. An improved fuel for compression ignition engines comprising a fuel oil containing a minor proportion of a chloro-nitro substituted normally gaseous parafiin hydrocarbon in which the chloro and nitro substituents are attached to a common carbon atom.

7. An improved fuel for compression ignition engines comprising a hydrocarbon fuel oil containing about 1 to 4% byweight of a chloro-nitro substituted normally gaseous paramn hydrocarbon in which the chloro and nitro substituents are attached to a common carbon atom.

8. The method of accelerating the ignition of Diesel cycle internal combustion engines which comprises admixing with the fuel. prior to ignition, a minor proportion of a chloro-nitro substituted normally gaseous paraflin hydrocarbon,

in which the chloro and nitro substituents are attached to a common carbon atom.

9. The method of accelerating the ignition of a Diesel cycle internal combustion engine which comprises introducing, in minor proportion, a

chloro-nitro substituted normally gaseous paratfin hydrocarbon, in which the chloro and nitro substituents are attached to a common carbon atom, to the combustion chamber of the engine LOUIS A. CLARKE. 

